“The most important thing I’ve accomplished, other than building the compiler, is training young people. They come to me, you know, and say, ‘Do you think we can do this?’ I say, ‘Try it.’ And I back ’em up. They need that. I keep track of them as they get older and I stir ’em up at intervals so they don’t forget to take chances.” — Grace Hopper

Grace Hopper was both an admiral of the US navy and a pioneer of computer science, introducing some concepts that are now fundamental to programming.

She tried to enlist in the navy at the beginning of the second world war but was rejected due to being too old (then aged 34) and had to wait a few years before being able to join the reserve.

At age 46 she wrote the very first linker (“a running compiler and nobody would touch it. They told me computers could only do arithmetic.”). She then started working on the idea of a machine-independent programming language, letting people program using human words instead of a machine-specific assembly, leading to the creation of the language COBOL at age 53.

At age 77 she was awarded the rank commodore (that would later be turned into admiral). She retired at 79, then the oldest active-duty commissioned officer in the United States Navy.